



















Book ILZ 





















/ 






Where They Are Found, 
he Manner of Their Production, 
Their Character and Their 
Uses in Mechanics. 



BY R. T. CRANE. 




' 




























Standard Metals 


Where They Are Found, 

The Manner of Their Production, 
Their Character and Their 
Uses in Mechanics. 




BY R. T. CRANE. 


— . * / 



fV c/// 


CHICAGO: 

Rand, McNally & Co., Printers. 
1896. 







Copyright, 1896, by R. T. Crane, Chicago. 




1 


* 




v \ 











CONTENTS. 

Page 

Introduction,. 5 

Copper, ..S 

Copper and Tin,.13 

Copper and Zinc,.15 

Hard Solder, -.17 

Copper, Tin, Zinc, and Lead, 18 

Seamless Drawn Brass and Copper Tubing, 20 

Lead,.22 

Lead Pipe Making,.25 

Shot Making, -.28 

Lead Alloys— 

Babbitt-Metal, - 29 (also 47; 

Type-Metal, - - - - 31 

Pewter,.32 

Zinc,.33 

Zinc Amalgamations, - 40 

Antimony, ------- 40 

Tin, -------- 42 


( 3 ) 




4 


CONTENTS. 


Tin Alloys— 

Page 

Babbitt-Metal, 

- 47 (also 29) 

Britannia-Metal, 

7 

Soft Solder, - 

49 

Plumbers’ or Wiping Solder, 

- 49 

Electro-Plating, - 

5 i 

Iron and Steel, ... 

- 52 

Malleable Iron Castings, 

69 

Welding, - 

71 

Tempering, .... 

74 

Wrought Iron Tubes, 

. 77 

Molding,. 

82 

Aluminum, .... 

- - - 87 


INTRODUCTION. 


The object aimed at in this book 
is to give, in a condensed form, the 
essential features of standard metals, 
thereby enabling students in manual 
training schools to readily acquire a 
fundamental knowledge of the subject. 

For the material I am largely in¬ 
debted to various publications and 
persons directly connected with the 
different lines discussed, but there is 
also a large portion of it that I have 
myself gained through a long personal 
experience in a manufacturing busi¬ 
ness wherein these metals are exten¬ 
sively used. 

I trust the reader will find the peru¬ 
sal of this work profitable. 

R. T. Crane. 


(5) 







STANDARD METALS. 


Where They are Found, the Man¬ 
ner of Tiieir Production, 
Their Character and 
Their Uses in 
Mechanics. 


It has not been thought necessary 
in this work to make a study of those 
metals the uses of which are confined 
principally to the arts and sciences. 
Those alone will be considered that 
are in common use — such as copper, 
lead, zinc, antimony, aluminum, and 
tin (with their alloys), also iron and 

( 7 ) 





8 


STANDARD METALS. 


steel. The fundamental principles of 
molding will also be discussed. 

These metals (with the exception of 
iron and steel) are all used in combi¬ 
nations. In some cases all (excepting 
aluminum) are combined, in other in¬ 
stances three of them, and in still 
others only two, in varying propor¬ 
tions. In describing the different 
combinations, each will be considered 
under the head of that metal which 
forms the largest proportion of the 
combination. 


COPPER. 

In the early ages of the world, copper 
was the most valuable metal, and, with 
the exception of iron, is so considered 
to-day, for the reason that, while other 
metals have greater value for special 


STANDARD METALS. 


9 


purposes, there is none which has so 
wide a range of use as copper. 

WHERE FOUND. 

As this metal exists in a natural state 
in nearly all parts of the world, and in 
that form is easily worked, it was par¬ 
ticularly valuable at a time when the 
art of reducing iron, zinc, and lead 
from their ores had not been acquired, 
and hence was extensively used at a 
very early period. 

In this country copper is found in 
large quantities in the neighborhood of 
Lake Superior, and in Montana, Utah, 
and Arizona. 

Metallic copper is found embedded 
in rock, in the form of masses, flakes, 
sheets, and threads. 

It is probable that the ancients, hav- 




10 


STANDARD METALS. 


ing no machinery or scientific knowl¬ 
edge such as is now available, worked 
only such copper as could be found 
“native,” and only in such bulk as per¬ 
mitted it to be conveniently handled by 
some simple method. 

By modern processes its extraction is 
mechanically conducted in a scientific 
manner on an exceedingly large scale, 
making it possible to produce copper 
profitably from a very low grade of ore 
— say four per cent — at a cost of about 
five cents per pound. 

Some grades of copper are contami¬ 
nated with a small percentage of iron, 
also with silver, lead, and antimony. 

To produce a commercially pure arti¬ 
cle, it is passed through a variety of 
processes, such as roasting, washing, 
smelting, poling, etc. 




STANDARD METALS. 


11 


Copper is a remarkably good conduc¬ 
tor of heat and electricity. 

It melts at 2,050 degrees Fahrenheit. 

USES. 

With the exception of iron, as previ¬ 
ously .stated, copper is the most useful of 
metals, on account of its strength, malle¬ 
ability, hardness, and indestructibility. 

In a pure state, after being rolled 
into sheets, it is used for a great variety 
of purposes, such as sheathing for 
wooden ocean vessels, for cooking-uten¬ 
sils, and for roofing. It is also widely 
used in breweries, distilleries, and sugar 
refineries, where, if iron were employed, 
it would be subject to oxidation. 

Another extensive use of this metal 
is in connection with all kinds of elec¬ 
trical appliances. 

Copper vessels are tinned when used 




12 


STANDARD METALS. 


for culinary purposes, or when liable to 
be filled with alkalies or other substan¬ 
ces which might dissolve the metal and 
render it poisonous. 

Copper is .seldom used in the form 
of a casting, for the reason that it has 
no special merit in any heavy form. 
Combinations with other metals are 
superior to this form of copper for 
general purposes. 

There is a theory that the ancient 
Egyptians and the prehistoric nations 
of America understood the art of har¬ 
dening copper, and used the tempered 
metal for making tools; but of this . 
there is no conclusive evidence, and 
even were it true, it is a lost art, only 
steel being now used for that purpose. 

Copper has been employed in coinage 
since the earliest ages. 



STANDARD METALS. 


13 


In mixing 1 metals, the metal requir¬ 
ing the highest temperature should be 
melted first. 

COPPER AND TIN. 

The most important of the combina¬ 
tions of which copper is a component is 
copper and tin. A very valuable one 
of this character is bell-metal, which 
is composed of 22^ per cent tin and 77-I 
per cent copper. 

It is said that the ancients used silver 
in their bells. However this may be, it 
is evident that bells of a beautiful tone 
can be produced from copper and tin, 
and that copper is the basis of all good 
bells. A great many steel bells are 
used in these later years, but they have 
not the sweet tone possessed by those 
composed of copper and tin. 



14 


STANDARD METALS. 


A combination consisting of one part 
of tin to six, seven, eight, or nine parts 
of copper, according to the use for 
which it is intended, produces a material 
of great tensile strength and hardness. 
The greater the proportion of tin, the 
harder the composition will be. This 
composition is of the greatest value for 
mechanical purposes, as hardness and 
strength are two of the most desirable 
qualities in nearly all metals. 

This alloy is of a reddish gold color, 
and is well known under the name of 
brass. When composed of one part 
tin to six or seven of copper, this alloy 
has great value as a wearing metal for 
journals, and is largely employed for 
that purpose. 

The drawback to its very extensive 
use in many ways is its hard and stub- 




STANDARD METALS. 


15 


born nature, which makes the working 
of it very expensive. For this reason 
the demoralization of trade has led 
to a modification of the composition 
by the addition of a little lead and 

zinc, thereby greatly toning down its 
nature. 

This latter composition is the metal 
of which we see so much. It is of a 
reddish color and is extensively used in 
the manufacture of such articles as 
steam-engine trimmings, brass cocks, 
valves, etc. 


COPPER AND ZINC. 

A composition of copper and zinc, 

containing from 25 to 40 per cent of the 

latter metal, is used in the production 

of SHEET BRASS. When containing a 
2 











16 


STANDARD METALS. 


medium amount of zinc, the color of the 
combination is a golden yellow; a smal¬ 
ler amount, giving it a beautiful green¬ 
ish cast, while a larger proportion pro¬ 
duces a whiter appearance. 

This composition has nearly all the 
merits of copper for almost every pur¬ 
pose. It is not only cheaper, on account 
of its alloy with zinc — a metal cost¬ 
ing only one-third to one-half as much 
as copper — but, being harder and more 
beautiful, it is adapted for a great variety 
of purposes for which copper is not suit¬ 
able. 

USES. 

This sheet metal is used principally 
as a substitute for sheet copper, its de¬ 
sirability being due in some cases to 
its cheapness, in some to its hardness, 
and in others to its beauty. It is 


STANDARD METALS. 


17 


employed in watch and clock work, also 
for chandeliers, and an almost endless 
variety of ornamental purposes. 


HARD SOLDER. 

An important combination of copper 
and zinc is that known as brazing- 
solder, a substance used to unite copper 
and brass. The proportions of this 
material are 45 per cent of zinc to 55 
per cent of copper. 

In order to use this solder it must be 
“grained.” This process is sometimes 
accomplished by casting the metal in 
the form of bars, then heating it to 
about 600 degrees, at which temperature 
it becomes brittle and is easily pounded 
into grains in a mortar. At other times 
the melted metal is poured from a height 




18 


STANDARD METALS. 


over a brush-broom, separating it into 
globules, which fall into water. 

This composition melts at a lower 
temperature than copper. 

When using this hard solder, it is 
mixed with a solution of sal ammoniac, 
and the parts to be joined are secured 
in position, the solder being applied to 
the joint. The copper is placed over 
the fire, and the temperature is gradu¬ 
ally raised until the solder melts and 
flows along the joint, care being taken 
that the temperature is not raised suffi¬ 
ciently to melt the copper. 

COPPER, TIN, ZINC, AND LEAD. 

There is an endless variety of combi¬ 
nations of these metals in use in the 
brass foundry business, the proportions 



STANDARD METALS. 


19 


varying according to the different 
purposes for which the castings are 
designed. 

It should be borne in mind that the 
addition of tin or zinc, or both, to cop¬ 
per has the effect of hardening it. 

A considerable amount of zinc tends 
to lessen the cost of the composition; 
but it also gives it a light color, which 
is undesirable for many purposes. To 
counteract this effect a small proportion 
of lead is* added, which produces a 
metal similar in color to a combination 
of copper and tin, but more easily 
worked. The resemblance of the two 
alloys is, in fact, so close that a skilled 
foundryman finds it difficult to judge 
of the quality of metal by its color, and 
can only determine its identity by either 
chipping or breaking it, when the in- 


20 


STANDARD METALS. 


ferior metal will be revealed bv its soft- 

«✓ 

ness and weakness. 

When strength and hardness are re¬ 
quired, the amount of lead and zinc 
used is proportionately lessened. 


SEAMLESS DRAWN BRASS AND 
COPPER TUBING. 

HOW MADE. 

The raw materials, which, for brass 
tubing, consists of about one-third spel¬ 
ter (unrolled zinc), and two-thirds cop¬ 
per, are first melted in a crucible. The 
proportions of this mixture may be 
varied according to the quality of tube 

desired. 

After being thus melted and mixed, 
the composition is poured into a mold, 





STANDARD METALS. 


21 


and around a bar that is supported in 
the mold, thus producing- a hollow cast¬ 
ing. This casting, when cooled, is 
removed from the mold and taken to 
the drawing room. 

The machine for drawing the tubing 
has somewhat the appearance of a long 
trough. In the center of it is perma¬ 
nently fastened a support for holding a 
die, through which the casting is drawn, 
the outside of the tubing being thus 
formed. The inside of the tubing is 
formed by a mandrel of proper size 
placed inside the casting, this mandrel 
being held in position by a long bar. 
The casting is clutched on one end by 
a clamp, or “dog ” as it is called, and is 
then drawn through the die and over 
the mandrel, which operation reduces 
its size and at the same time gives it a 



22 


STANDARD METALS. 


finish. This drawing process is re¬ 
peated again and again, each time 
through a smaller die, until the tubing 
is brought down to the diameter and 
thickness required. As drawing has 
the effect of hardening the metal, it is 
necessary that the tubing shall be an¬ 
nealed after each drawing; otherwise it 
would become so hard and brittle as to 
break while being drawn. Annealing 
consists in heating the metal to a red 
heat and then allowing it to cool grad¬ 
ually. 


LEAD. 

Lead is another of the highly valuable 
metals. Its existence was known of in 
the earliest historic times, but it was 
then considered of little importance. It 
is supposed to have been discovered at a 


STANDARD METALS. 


23 


later date than either copper or tin. 
We find, in the ruins of Pompeii, that 
it was used there, during the first cen¬ 
tury, in the form of water-pipe. 

WHERE FOUND. 

Lead ore is found abundantly, among 
other places, in Saxony, Bohemia, Eng¬ 
land, Spain, and the United States. 
The ores worked to the largest extent 
in the United States are those found in 
the valley of the Mississippi. Enormous 
deposits exist in Missouri, Iowa, Illinois, 
and Wisconsin, embedded in crevices 
and pockets in the lower or Silurian 
rocks known as “Galena Limestone.” 
These deposits have been worked only 
since about 1820, although their exist¬ 
ence had then been known for more 
than a century. 



24 


STANDARD METALS. 


Nearly all the lead of commerce is 
obtained from Galena ore, which, when 
pure, consists of almost 87 per cent lead 
and 13 per cent sulphur. It nearly 
always contains silver, which is some¬ 
times present in quite large quantities, 
besides arsenic, copper, iron, zinc, and 
antimony. A large amount of lead is 
produced from the working of silver 
mines in Colorado, New Mexico, Utah, 
and Montana. 

The smelting of Galena is performed 
in a reverberatory furnace, after hav¬ 
ing been washed, and a little lime 
usually added. The lead smelting 
process closely resembles the reduc¬ 
tion of copper, that is, it is a de¬ 
sulphurization. Whilst melting, the 
sulphur passes off, leaving metallic 
lead behind. 


STANDARD METALS. 


25 


USES. 

The extensive use of lead is due to its 
indestruetibility, ease of working-, and 
cheapness. Its largest uses are found 
in the plumbing business (where it is 
employed in the form of pipe and sheets) 
and in the manufacture of shot and 
bullets the value of this metal for the 
two latter purposes being due to its high 
specific gravity. It is also employed 
quite commonly as a coating for sheet- 
iron, a combination frequently .substi¬ 
tuted for tinned iron or galvanized iron. 
Lead as well as zinc is also used in the 
manufacture of paints. 

LEAD PIPE MAKING. 

The machine by which this work is 
performed is composed of a hydraulic 



2G 


STANDARD METALS. 


cylinder and a lead cylinder. In the 
hydraulic cylinder is what is called a 
“water ram,” and on top of this 
water ram is placed the lead cylinder, 
the hydraulic pressure being applied at 
the bottom of the water ram. 

In the center of the lead cylinder 
is a steel core, and as the melted 
lead is run into this lead cylinder it 

congeals, forming a solid mass around 
the steel core. 

A lead ram is hung directly over the 
lead cylinder, fitting it exactly ; and in 
the bottom of this ram is a die, having 
in its center a hole the exact size of the 
outside of the pipe. 

It will be seen that by this arrange¬ 
ment the space which is left between 

the center core in the lead cylinder 
and the die above it is just the thick 



STANDARD METALS. 


27 


ness and size of the pipe that is to be 
made. 

After the lead has been melted and 
run into the cylinder and has congealed, 
the hydraulic pressure is applied in the 
cylinder, which raises the lead cylinder 
up against the lead ram (which ram, it 
will be remembered, fits the lead cylin¬ 
der exactly). The pressure applied is 
so great (sometimes being as high as 
28,000 pounds to the square inch) that 
it forces the congealed lead to flow out 
in a “ stream,” as it might be called, 
which completely fills the space between 
the steel core and the die, the latter 
forming the outside of the pipe, while 
the former makes the inside. 

As the pipe comes out of this 
machine it is coiled up and is then 
ready for use. 


28 


STANDARD METALS. 


SHOT MAKING. 

For this work a tower is required, 
which is necessarily about 300 feet in 
height, in order that the melted lead 
(which, as explained later, is dropped 
from the top of the tower) may become 
congealed before reaching the bottom. 

The lead, in the form of “pigs,” is 
taken to the top of the tower and there 
melted in kettles, and upon becoming 
liquid is poured over a sieve, through 
which it falls in drops. These drops, as 
they fall through the air, take a spherical 
shape, and upon reaching the bottom 
are received in a vat containing either 
water or oil. From this vat the pellets 
are removed to a machine which sepa¬ 
rates the different sizes. This machine, 
which somewhat resembles a bureau in 


STANDARD METALS. 


29 


appearance, and is so arranged that it 
will rock, contains a series of shelves, 
each of which is perforated to allow 
shot of a certain size to pass through. 
The arrangement of these shelves is 
such that the largest shot will stop on 
the first shelf, the next size on the sec¬ 
ond, and so on downward until the 
bottom is reached, where the .smallest 
size is received. 

The size of the shot can also be gov¬ 
erned to a certain extent by the size of 
the perforations in the sieve at the top 
of the tower. 

LEAD ALLOYS. 

BABBITT-METAL. 

This is a composition that is used 
extensively as a substitute for brass, in 


30 


STANDARD METALS. 


the lining of journal bearings. To 
make such a bearing, the shaft for 
which it is required is placed in posi¬ 
tion in its recess, or cavity, and then 
the melted babbitt-metal is poured in 
around it and allowed to cool, thus 
forming the bearing for the shaft. 

The value of babbitt-metal for this 
purpose lies in the fact that it has all 
the merits of brass as a wearing mate¬ 
rial, and at the same time melts at 
a much lower temperature; and, also 
being of a very fluid nature when 
melted, it may be poured into the cav¬ 
ities around a shaft, and the expensive 
operation of fitting brass to these places 
thus be dispensed with. 

What is called the “ genuine,” or su¬ 
perior babbitt-metal, is described under 
the heading of Tin Alloys. But there 


STANDARD METALS. 


o 1 
ol 

are a variety of cheaper grades of this 
material, in which le'ad is very exten¬ 
sively used alloyed with antimony, or 
with antimony and tin. While these 
compositions are not so good as the 
“genuine,” they are of sufficient merit 
for a large variety of cheap machinery, 
and are extensively used in the repair¬ 
ing of agricultural implements, and 
other grades of cheap machinery. 

An immense quantity of the combi¬ 
nation of lead and antimony is produced 
by the silver smelters, a market for 
which is found in the production of 
babbitt-metal. 


TYPE-METAL. 

While we all appreciate the great 
value of the printing-press, inventions 
of no less importance to the world are 

3 


32 


STANDARD METALS. 


those of type-metal and the type-ma¬ 
chine, without which the art of printing 
would never have reached its present 
universality and perfection. 

Type-metal is composed of lead al¬ 
loyed with antimony and a small per¬ 
centage of copper, which combination is 
practically the only one adapted to the 
purpose, its special fitness arising from 
its extreme fluidity, durability, and 
cheapness. While tin might have been 
used, it would not have been nearly so 
well adapted to this end, besides being 
much more expensive than the combina¬ 
tion just described. 

PEWTER. 

Pewter, which years ago was quite 
extensively used for spoons, cups, and 
tableware, is a cheap substitute for 


STANDARD METALS. 


33 


britannia-metal. It is composed of 84 
per cent lead, 15 per cent tin, and 1 per 
cent antimony. 


ZINC. 

Spelter, as block zinc is termed, is a 
metal of bluish-white color, and about 
as heavy as iron. 

When exposed to the air it turns 
gray, and finally becomes whitish, from 
oxidation. 

Its fracture is crystalline with high 
lustre, and when cast it is rather brittle. 

At a temperature of between 220 and 
300 degrees Fahrenheit, it is ductile, 
and can be rolled into sheets. At 400 
degrees it is extremely brittle. It 
melts at 790 degrees, and burns at 
960 degrees, with a green and white 
flame. 


34 


STANDARD METALS. 


While zinc appears to have been 
known to the ancient Greeks, it did not 
become a regular article of manufacture 
until about 1720, in Germany, and in 
England, fifteen or twenty years later. 
It was first manufactured on a large 
scale in Belgium, in 1807. In the United 
States it has been manufactured since 
about 1850, being first smelted in Beth¬ 
lehem, N. J. 

WHERE FOUND. 

Zinc is not provided by Nature in 
metallic form. Its ores are principally 
the carbonate of zinc, the silicate of 
zinc, the sulphide of zinc, and the red 
oxide of zinc. 

They are generally found associated 
with the ores of lead, and are widely 
distributed. 



STANDARD METALS. 


35 


In the United States they are found 
at Stirling - , N. J.; Bethlehem, Pa.; in 
Virginia, West Virginia, East Tennes¬ 
see, Wisconsin, Missouri, Kansas, and 
Arkansas; also in Maine, New Hamp¬ 
shire, Illinois, Kentucky, and in the 
mineral districts of Colorado, New 
Mexico, Montana, Utah, etc. 

The principal seats of the zinc smelt¬ 
ing industry are in Germany (in Silesia 
and Northwestern Germany) and Bel¬ 
gium; also in France and England, 
and in the United States — especially 
in Illinois (near La Salle), in Missouri, 
and Kansas; also in Virginia, New Jer¬ 
sey, Tennessee, etc. 

HOW PREPARED. 

Preparatory to smelting, the carbon¬ 
ate of zinc and silicate of zinc ores are 


36 STANDARD METALS. 

calcined to make them porous and to 
drive out the carbonic acid and water. 

The zinc blende, as this pulverized 
ore is termed, is ground fine and cal¬ 
cined in reverberatory or muffle fur¬ 
naces of various shapes, at a high 
temperature, while air is admitted. 
The sulphur combined with the zinc 
in the blende then passes off as sul¬ 
phurous acid, from which sulphuric 
acid can be manufactured in the .same 
manner as from iron pyrites. 

The ores thus prepared, having be¬ 
come essentially oxide of zinc, are 
mixed with fine anthracite bituminous 
coal or coke and charged in retorts 
in which they are exposed to intense 
heat. These retorts are pipes of fire¬ 
clay, closed at one end, and ranged in 
furnaces so that their mouths pass 


STANDARD METALS. 


37 


through the sides of the furnaces. In 
the mouths of the retorts short clay 
pipes, called condensers, are inserted, 
which protrude from the furnace. 

The zinc, reduced from the ore and 
volatilized in the retorts by the joint 
action of the heat and the carbon, is 
condensed in the cooler condensers, 
and from them flows in fluid form into 
the molds. This process is called 
“ distillation. ” 

Zinc, or what is commonly called 
“spelter” of commerce, is thus made. 

USES. 

Spelter is principally used in con¬ 
junction with copper for making brass. 

Another large and important use to 
which zinc is put is that of galvanizing 
(coating) iron in the shape of sheets, 


38 


STANDARD METALS. 


wire, piping, and an almost endless 
variety of other forms used in the 
trades. The galvanizing process is 
similar to that followed in tinning 
iron, described under the head of tin. 

This metal, as commonly used in 
manufactures, is in the form of sheet 
zinc or zinc plates. 

The process of rolling this metal is 
similar to that of copper, but its tem¬ 
perature, while it is being treated, must 
be kept at a little above the boiling 
point of water, to secure the necessary 
malleability. 

A peculiar effect is produced by the 
rolling. From the pressure it under¬ 
goes, the crystalline texture of the 
zinc (which before rolling is brittle) ' 
is changed, and it is rendered much 
tougher, so that it can be bent, pressed 


STANDARD METALS. 


39 


into shapes, stamped, and spun, and is 
made eapable of receiving- a high polish. 

Sheet zinc, on account of its cheap¬ 
ness, holds an important place, as a sub¬ 
stitute for copper and brass, it being 
about one-half the price of brass and one- 
third the price of copper. Like these 
metals, it is not subject to destruction 
by oxidation, as is the case with iron. 

Sheet zinc being produced with a 
durable high polish or finish, is particu¬ 
larly valuable to the stove trade. 

It is also largely used for making 
stamped and spun ornaments in the 
chandelier and other trades, and for 
parts of buttons and cartridge-cases. 

To a limited extent it is utilized by 
engravers and in making architectural 
ornaments. 

Zinc is extensively employed in the 



40 


STANDARD METALS. 


production of paint and in galvanic bat¬ 
teries, but these uses are foreign to this 
study. 

ZINC AMALGAMATIONS. 

Zinc will not amalgamate perfectly 
with tin or lead, or with tin and lead ; 
but it will amalgamate with copper, 
or with copper, tin, and lead. It 
is exceedingly valuable in these com¬ 
binations, though it is only used 
as an alloy, which fact should not 
be lost sight of in considering the 
merits of this metal. 

ANTIMONY. 

Antimony is a grayish white, crystal¬ 
line, and lustrous metal, of moderate 
hardness, extreme brittleness, inferior 
tenacity, peculiar taste and odor, and is 


STANDARD METALS. 


41 


not subject to oxidation. It melts at 
840 degrees Fahrenheit. 

Though this metal was known to the 
ancients, we have no record of its hav¬ 
ing been used by them for any im¬ 
portant purpose. 

WHERE FOUND. 

Antimony is found in great abun¬ 
dance in Borneo, and there are also con¬ 
siderable deposits in England, France, 
and Hungary. The most common form 
of this ore is the sulphuret. This metal 
is also found in abundance in the Rocky 
Mountain section of North America, 
especially in California and Nevada, 
but in this country it is always found in 
combination with lead, in which form it 
is sold and used, the pure article being 
imported. 


42 


STANDARD METALS. 


The method, used in the reduction of 
this metal is similar to that employed 
in the reduction of lead. 

Antimony is only valuable as an alloy, 
never being used by itself nor as the 
largest proportion of a combination. Its 
merits and uses are therefore considered 
elsewhere in this book in connection 
with the combinations into which it 
enters. 


TIN. 

While very little is popularly known 
of tin, except in its use as a coating for 
iron — as in tinware — it is really a most 
beautiful metal, and is valuable for many 
other purposes. 

It resembles silver in every respect, 
except that it is slightly more subject to 
oxidation or tarnishing. 


STANDARD METALS. 


43 


When bent, it makes a crackling sound 
known as the “cry of tin.” 

It has great malleability, its conduc¬ 
tivity is low, and it melts at 443 degrees 
Fahrenheit. 


WHERE FOUND. 

Tin is not yet found in paying quan¬ 
tities in this country. We-depend for 
our supply upon England, Australia, 
Malacca, Germany, and Banca. 

It is sometimes found in a metallic 
state, but generally exists as an oxide, 
the most common form being a dioxide, 
called “ stream tin.” It is found in veins 
in the primitive rocks. 

REDUCTION. 

Much care is required in dressing and 
assorting it. The ore is stamped,washed, 


44 


STANDARD METALS. 


weathered a few days, and calcined, 
then again weathered and washed, and 
afterward smelted in a reverberatory 
or a blast-furnace. It is finally refined, 
as in the case of copper, by smelting and 
poling. 

USES. 

Tin is most extensively used as a coat¬ 
ing for sheets of iron, making what is 
known as “ tin-plate.” These iron sheets 
are first rolled to the desired thickness, 
and then immersed in a bath of diluted 
sulphuric acid to remove the oxide, 
after which they are dipped in a weak 
solution of muriatic acid, and finally 
passed through a bath of melted tin, 
the tin adhering to the plate. 

Tin is quite largely used in the pro¬ 
duction of tin-foil, which is used for 


STANDARD METALS. 


45 


wrapping tobacco and other materials 
which require to be protected from the 
action of the atmosphere. The method 
of manufacturing tin-foil is interesting 
and ingenious. First, a tin pipe is 
made of a thickness relative to its dia¬ 
meter. This pipe is then filled with 
molten lead, and afterward the combi¬ 
nation in that form is rolled or beaten 
out to the extreme thinness required. 
Tin-foil is thus seen to be in reality 
lead-foil, with a thin covering of tin. 
Thicker sheets amalgamated with mer¬ 
cury are employed for silvering mirrors ; 
also for purposes connected with the 
generation and use of electricity. 

Tin is used to a limited extent for 
making pipe as a substitute for lead, 
being less liable to corrode and contam¬ 
inate water. The pipe is sometimes 


46 


STANDARD METALS. 


made wholly of tin, while in other 
cases it is used as a lining- for lead pipe. 

The cleanly and innocuous qualities 
of tin make it valuable as a coating for 
culinary utensils. 

The production of tin has increased 
enormously during late years, owing to 
the growing demand for tin-plate in the 
canning industries and as a material for 
roofing. Our supply of tin-plate here¬ 
tofore has come entirely from England, 
being one of the largest items of our 
importation, but it is now being made 
in considerable quantities in this 
country. 


TIN ALLOYS. 

Being a comparatively costly metal, 
tin is only used to a limited extent in a 
pure state, except in the form of tin- 


STANDARD METALS. 


47 


plate, as previously stated. As an alloy, 
however, it is invaluable, being- of such 
merit in this respect that its expense is 
not a bar to its use for this purpose. 

It is a curious fact that the addition 
of a little copper hardens tin, and that 
a small proportion of tin also has the 
same effect upon copper. 

BABBITT-METAL. 

An extensive and extremely valuable 
use is made of tin when alloyed with a 
small percentage of copper and anti¬ 
mony, forming a superior grade of bab¬ 
bitt-metal known as “genuine,” which 
is employed, as already explained, in 
the higher grades of machinery. 

BRITANNIA-METAL. 

Tin alloyed with a very small amount 
of copper (to harden it) produces britan- 
nia-metal. 

4 


48 


STANDARD METALS. 


SOLDERS. 

An important use of tin as an alloy 
is in the production of solder, which is 
a composition used to join metals by 
fusing it upon the surfaces of contact, 
thereby obtaining a more or less firm 
and tenacious union. 

The essentials of a good solder are 
that it shall have an affinity for the 
metals to be united, that it shall melt at 
a considerably lower temperature than 
those metals, and that it shall be strong, 
tough, and uniform in composition. 

There are many varieties of solder, 
such as soft solder, plumbers’ or wiping 
solder, hard solder (already described 
under the head of copper and zinc), and 
special solders composed of various 
alloys of copper, zinc, lead, tin, bis¬ 
muth, gold, and silver. In this work, 


STANDARD METALS. 


49 


however, we shall only consider those 
used for common purposes. 

SOFT SOLDER. 

This is an alloy of tin and lead, con¬ 
taining from fifty to sixty per cent of 
the former metal, and has its most 
extensive use in the tinners’ trade, 
and in joining light metal articles 
not subject to great strain. When 
using this solder the surfaces to be 
joined are first cleaned from oxide, 
and then a fluid, composed of diluted 
muriatic acid in which a little zinc 
is dissolved, is applied as a flux. In 
place of this solution, resin is some¬ 
times employed. 

PLUMBERS’ OR WIPING SOLDER. 

This solder, which is composed of 40 
per cent tin and 60 per cent lead, is 


50 


STANDARD METALS. 


used in the plumbing trade for making 
joinings. 

Where a faucet is joined to a piece of 
pipe, or two pieces of pipe are joined 
together, an enlargement is observed. 
This enlargement consists of the solder, 
and is essential to the strength of the 
work. 

An exceedingly interesting feature of 
plumbers’ solder is the fact that, at a 
certain temperature, it takes the form 
of a pliable mass, which is easily handled 
and molded to produce the joints re¬ 
ferred to. This operation is as follows: 

The materials to be joined are first 
freshly tinned at the points of contact, 
to remove the oxide, and then firmly 
placed and secured in position. The 
melted solder is poured on these parts 
for the purpose of heating them. As 


STANDARD METALS. 


51 


the parts become hot the solder 
becomes cool, taking- on the pliable 
form above mentioned, and is easily 
manipulated by the mats in the hands 
of the mechanic, when the joining is 
completed. 

ELECTRO-PLATING. 

By the coating of iron with tin, zinc, 
or lead, a most desirable effect is pro¬ 
duced—•namely: A combination of 
strength with indestructibility, the iron 
giving strength, and the tin, zinc, or 
lead providing the indestructible pro¬ 
tection. 

This principle is carried to an almost 
unlimited extent, by means of the gal¬ 
vanic battery, in the comparatively new 
art of electro-plating, which originally 
was introduced for the economical use 


52 


STANDARD METALS. 


of the valuable metals in works of util¬ 
ity and art, such as coating- brass with 
silver and gold. 

But more recently the art of electro¬ 
plating is being applied on a broader 
scale, being used, for instance, to coat 
statuary and a great variety of articles 
with copper or brass. This application 
of the art promises to be an important 
modifying factor in these lines of work, 
as it makes it possible to coat iron 
articles with these metals, a process 
which is impracticable by the ordinary 
methods followed in coating iron with 
tin, zinc, or lead. 


IRON AND STEEL. 

Iron is the most useful and also the 
cheapest of all metals, and, fortunately, 


STANDARD METALS. 


53 


is the most widely diffused over the 
earth’s surface of any, except, possibly, 
aluminum. 

Iron is practically never found in 
native metallic state, but always in 
chemical composition with some other 
substance and mixed with earthy impu¬ 
rities. Such material is called iron ore. 

The principal ores of iron are the 
carbonate and oxide , and it is from the 
latter that by far the larger part of the 
world’s supply is obtained. 

Oxide of iron exists in three different 
conditions, forming the three iron ores 
commonly known to commerce. These 
are: 

ist. The lower oxide or protoxide of 
iron, called limonite , or brown hema¬ 
tite, which contains from 30 to 50 per 
cent of metallic iron. 


54 


STANDARD METALS. 


2d. The higher oxide or peroxide of 
iron, called hematite , containing from 50 
to 68 per cent of metallic iron. 

3d. A combination of these two 
oxides, forming a magnetic oxide called 
magnetite , containing from 60 to 72 per 
cent of metallic iron. 

The immense deposits in the Lake 
Superior region consist almost Avholly 
of the second class, or hematite. 

Metallic iron is obtained from the 
ores by reducing them in a high furnace 
of peculiar shape, called a blast furnace. 
Into this furnace the ore is introduced, 
together with the fuel necessary to 
reduce it, and some material called a 
flux, the purpose of which is to unite 
with and remove the earthy impurities 
associated with the ores. The flux usu¬ 
ally used with oxides of iron is limestone. 


STANDARD METALS. 


55 


The iron produced in the blast fur¬ 
nace is raw or crude iron, known as 
cast iron or pig iron , so called from its 
being cast in short, thick bars or pigs. 
It is crystalline in structure, and brittle, 
the size of its crystals and its brittleness 
varying according to the condition of 
the carbon in the iron. 

Carbon in pig iron exists in two 
conditions, namely, combined and gra¬ 
phitic. That is to say, part of the 
carbon is chemically combined with 
the iron and part exists in a free state 
as graphite. 

Pig iron is graded by its fracture into 
four great classes, viz.: No. /, No. 2 , 
mottled , and white. 

No. 1 iron is dark gray in color, and its 
crystals are large and lustrous. In this 
the carbon exists largely in the gra- 


56 


STANDARD METALS. 


phitic state, it being that substance that 
makes the large crystals. 

No. 2 iron is a lighter gray, and the 
crystals are smaller, and the grain 
closer. In this iron the carbon is more 
largely combined' and less graphitic 
than in the No. i iron. 

Mottled iron has a very close fracture, 
and presents the peculiar appearance 
of little white spots scattered closely 
through the gray, whence arises its 
name, “ mottled.” 

In this the carbon exists about equally 
as graphitic and combined. 

White iron has a very close, dense 
fracture, entirely white. The carbon 
in this is almost entirely combined. 

White iron is the most brittle and of 
the poorest quality, while No. i iron is 
the least brittle, and the best in quality. 


STANDARD METALS. 


57 


No. i iron is soft, while white iron is 
so hard that it can not be cut with steel 
tools. 

Pig iron is disposed of in three ways, 
viz.: 

i st. It is used in foundries for mak¬ 
ing castings. 

2d. It is converted into wrought iron 
by the puddling process. 

3d. It is converted into steel. 

In the foundry pig iron is practically 
unchanged in its nature, excepting a 
partial refining which takes place in 
melting. 

In conversion into wrought iron, the 
pig iron loses its crystalline structure, 
by puddling, which converts it into a 
fibrous structure, giving it the tough¬ 
ness, tenacity, and ductility which we 
find in wrought iron. 


58 


STANDARD METALS. 


Wrought iron is the only condition 
in which iron exists as a fibrous metal. 
Both pig iron and steel are crystalline 
in structure. 

The process of puddling consists in 
melting pig iron on the bed of a fur¬ 
nace of peculiar construction, where, 
under the influence of intense heat, 
most of the impurities are oxidized and 
removed in the slag. The removal of 
the impurities is facilitated by con¬ 
stantly stirring the mass of metal with 
a long bar of iron. 

Toward the close of the operation 
the metal becomes pasty, and is finally 
accumulated into ball-shaped masses of 
iron weighing 200 or 300 pounds each. 
These are treated under a heavy ham¬ 
mer or revolving squeezer to remove 
the slag, and form the ball into a more 


STANDARD METALS. 


59 


compact block or “ bloom," which is then 
rolled into bars. 

The furnace in which the puddling 
process is carried on is known as a 
reverberatory furnace, so called, from the 
fact that the flame from the grate is 
directed by a bridge wall up against 
the roof, and thence deflected or “ rever¬ 
berated ” down upon the mass of metal, 
then out to the chimney. In this way 
the full power of the flame is thrown 
directly upon the material to be heated. 

The third, and, of late years, by far 
the most general use of pig iron, is for 
the manufacture of steel. This is accom¬ 
plished in two ways or processes, viz.: 

FIRST, THE OPEN HEARTH PROCESS. 

This consists of melting the pig iron 
in a large furnace and subjecting it to 


60 


STANDARD METALS. 


great heat, meanwhile affording a free 
access of air, which, at the high temper¬ 
ature attained, combines with the car¬ 
bon in the iron and passes off as car¬ 
bonic acid gas, leaving the metal nearly 
or quite free from carbon. The silicon 
of the iron likewise is oxidized and 
removed. In this way the iron is 
changed to steel. 

This process occupies several hours 
for each' charge, and the operation is 
stopped at the precise point of decar¬ 
bonization to which it is desired to 
bring the metal. 

SECOND, OR BESSEMER PROCESS. 

To accomplish practically the same 
results in a very much shorter time, a 
second method, called after its inventor, 
the Bessemer process, is followed. 


STANDARD METALS. 


61 


This process consists in introducing 
into a pear-shaped vessel, termed a 
“ converter,” a charge of molten pig iron, 
and then forcing into it large quantities 
of air, which, as in the open hearth proc¬ 
ess. combines with and removes the 
carbon and silicon. On account of the 
large excess of air forced upon the iron, 
the combustion takes place more rap¬ 
idly than in the first process, and the 
iron is converted into steel in ten or 
fifteen minutes. 

In this process it is impossible to stop 
at the precise point of decarbonization 
required ; therefore, the carbon is prac¬ 
tically all removed, and then the re¬ 
quired amount is obtained by adding 
iron rich in carbon. 

Having now studied the manufacture 
of steel, let us inquire what steel is. 


62 


STANDARD METALS. 


Steel is simply a modified form of 
iron, differing from it mainly in the 
lesser amount of chemical impurities 
which it contains, and in the possession 
of greater strength. 

The principal difference between pig 
iron and steel is the amount of carbon 
each contains, pig iron containing about 
4 per cent and steel from .05 per cent to 
.5 per cent. The finer grades of steel, 
such as those used for tools and cutlery, 
sometimes contain as much as 1 per 
cent. 

The amount of carbon contained in 
steel is the chief factor that determines 
its character. Steel is therefore graded 
by the amount of carbon it contains. 

Steel that must have great tough¬ 
ness and elasticity, such as is required 
for boiler plates, is very low in car- 


STANDARD METALS. 


63 


bon, running- from .05 per cent to .1 
per cent. 

The higher the carbon runs the 
harder and stronger is the steel, but less 
elastic and ductile. Therefore steel for 
rails, which are required to be hard and 
to resist the wear and friction of car- 
wheels, but in which elasticity is not so 
essential, runs from .3 per cent to 
.5 per cent in carbon. 

It is essential that steel be as nearly 
chemically pure as possible, with just 
sufficient carbon to give to it its required 
physical characteristics, as all other 
elements of every kind when admixed 
with steel have a more or less deleterious 
effect. 

The troublesome elements that are 
met with most frequently in iron and 

steel are sulphur and phosphorus. 

5 


64 


STANDARD METALS. 


Phosphorus until very recent years 
has been the bugbear of the steel manu¬ 
facturer, for, if it once creeps into the 
pig iron it is impossible to remove it in 
its conversion into steel, and phorphorus 
is very harmful in its effect upon steel. 

The pig iron, therefore, from which 
steel is to be made has to be produced 
from ore as low as possible in phos¬ 
phorus, and as such iron is used in the 
manufacture of Bessemer steel, it is 
called Bessemer iron. 

Within the last few years, however, 
a method has been discovered of remov¬ 
ing the troublesome phosphorus during 
the conversion of iron into steel, either 
by open hearth or Bessemer process. 

Phosphorus is an acid, while iron is a 
base . Therefore the strong affinity that 
every acid has for a base impels the 


STANDARD METALS. 


65 


phosphorus to unite with the iron. If, 
now, a stronger base is presented, the 
phosphorus will unite with that rather 
than with the iron. This is accom¬ 
plished in the manufacture of steel by 
lining the furnace or vessel with lime, 
which is a much stronger base than 
iron. Therefore, after the pig iron is 
melted the phosphorus leaves the iron 
and unites with the furnace lining, or 
with the slag that is formed of the lime, 
and is almost wholly removed. This is 
what is known as the basic process. 

BLISTER STEEL. 

One of the numerous miscellaneous 
small processes of steel making is the 
manufacture of blister steel by what is 
known as the “ cementation ” process. 


66 


STANDARD METALS. 


This consists of subjecting bars of 
iron imbedded in charcoal and inclosed 
in air-tight vessels or compartments to 
a high heat for a long period. At the 
high temperature the iron bars “ soak 
in ” and absorb the carbon of the char¬ 
coal, thereby converting the iron into a 
high carbon steel. 

The surface of the bars at the end 
of the process is rough and blistered ; 
hence the name. 

Blister steel is principally used for 
facing iron in such tools as hammers, 
anvils, and various blacksmith’s tools 
on account of the special property it has 
for uniting with iron in welding. 

TOOL OR CAST STEEL. 

This is the great steel of commerce, 
and as its use, like that of cast and 


STANDARD METALS. 


67 


wrought iron, is almost universal, it is 
unnecessary to dwell upon the details 
of its employment. 

It is made from blister steel, which is 
broken up into small pieces and care¬ 
fully selected, melted in a plumbago 
crucible, then poured into cast-iron 
molds, forming bars, which are then 
hammered and rolled into the desired 
shapes and sizes for the market. 

The quality of this steel is regulated 
by the quality of iron used in its manu¬ 
facture and the thoroughness with 
which it is worked under the hammer 
and in the rolls. 

QUALITY OF WROUGHT IRON. 

The quality of wrought iron is known 
by its fiber; that is, a good quality ought 
to stand a large amount of bending when 


68 


STANDARD METALS. 


cold, and when broken should show a 
fibrous structure. 

Should it break off short, after the 
manner of cast iron, it is evident that 
the iron is of poor quality. 

In testing - iron in this manner it 
should not be nicked, as that produces 
crystallization. 

The foregoing is the merest outline 
of the manufacture of iron and steel, no 
attempt having been made to examine 
into the many elaborate details of the 
processes. In the case of iron espe¬ 
cially, the processes are so many, and so 
varied, and are so continually present¬ 
ing new phases that the knowledge and 
ingenuity of the iron master are contin¬ 
ually taxed, and the manufacture of 
iron and steel is stamped as one of the 
most intricate of the useful arts. 


STANDARD METALS. 


69 


MALLEABLE IRON CASTINGS. 

In another place we have explained 
the method used in the manufacture 
of wrought iron, which material is* 
in fact, malleable iron. This wrought 
iron is made malleable in the form of 
bars and is then forged on an anvil 
in the shape desired for use. But in 
the manufacture of malleable iron cast¬ 
ings this process is reversed, the pig 
iron as it comes from the blast fur¬ 
nace being first cast in the form in 
which it is to be used, and afterward 
made malleable. This, it will readily 
be seen, is a beautiful and radical 
departure from the original methods 
of making wrought iron, for by it the 
cast iron can be easily melted and cast 
in any complicated form desired and 
afterward made malleable, thus en- 


70 


STANDARD METALS. 


abling the manufacturer to produce at 
much less cost articles equaling in 
quality and surpassing in complexity 
of design those made from forged 
wrought iron. Following is a brief 
description of this process: 

After the castings are made they are 
packed in cast-iron pots, the space 
around the castings being filled with 
oxide of iron. Then the pots contain¬ 
ing the castings are placed in a furnace 
and subjected to a strong heat, which 
has the effect of extracting the carbon 
from the castings. In the case of 
wrought iron this is done in the pud¬ 
dling process. 

This method of manufacturing mal¬ 
leable iron was invented in America 
about fifty years ago, and the business 
has now grown to such large propor- 


STANDARD METALS. 


71 


tions that it is impossible to here enum¬ 
erate the great variety of uses to which 
it is applied. The American manu¬ 
facturers have always held an advanced 
position in this art, and have done more 
in this line of manufacturing than has 
been accomplished by all other coun¬ 
tries combined. 

WELDING. 

The property of welding is possessed 
by wrought iron and soft steel, whereby 
two separate bars or other pieces can 
be joined or united together under the 
influence of heat and pressure so as to 
form one continuous or coherent piece. 
The two metals mentioned are the only 
ones possessing this property. 

The pieces to be joined are heated to 
a nearly white heat known as “welding 




72 


STANDARD METALS. 


heat,” after which they are placed either 
closely together or one on top of the 
other, and by blows of a hammer or 
the squeezing effect of rolls or a power 
press, are forced into a close union, 
making the two pieces substantially 
one. 

While to form a strong and substan¬ 
tial weld it is necessary, as just ex¬ 
plained, to apply some pressure in order 
to force together all of the surface to 
be welded, it is interesting to note that 
these metals possess a strong tendency 
to unite or adhere to each other under 
a welding heat, as is shown by the fact 
that upon reaching this heat the pieces 
of metal will become welded together 
to a certain extent if allowed merely to 
touch each other without the applica¬ 
tion of any pressure. 


STANDARD METALS. 


73 


In a good weld the welded part 
should be as strong as any other part 
of the bar. To obtain this strength 
the ends of the bar to be welded are 
thickened by being hammered up, or 
“ up-set,” which allows the welding 
pressure to be applied without reduc¬ 
ing the size at the weld to less than 
the size of the remainder of the bar. 
After being “up-set,” the ends of the 
bars are also beveled, in order to get 
a liberal amount of surface to weld. 

The blacksmith, in preparing two bars 
for welding, usually throws a little white 
sand or borax upon the two heated sur¬ 
faces before they are brought together 
for welding. The purpose of this is to 
form a flux which, by the chemical 
combination of the sand or borax with 
such rust, scale, or dirt as may be upon 


74 


STANDARD METALS. 


the surfaces of the two bars, forms an 
easily fusible material which cleans the 
surfaces of the two bars just at the time 
they are ready to be joined. 

It is only possible to weld together 
such steels as are very soft or contain a 

J 

very small percentage of carbon. The 
hard steels, such as tool steels, are not 
capable of being welded because of the 
large percentage of carbon which they 
contain. The purer the steel or iron 
the more easily it is welded. Hard 

j 

steel and iron are welded as in the case 
of axes and carpenters’ chisels where 
only the cutting edge is of steel and 
the other portions are of iron. 

TEMPERING. 

While in many cases steel is used on 
account of its strength and wearing 


STANDARD METALS. 


75 


qualities alone, a probably no less im¬ 
portant use made of it is in the manu¬ 
facture of tools and springs. For these 
purposes it requires to be tempered, as 
until that is done the steel is soft. 

By “tempering” is meant hardening 
the metal to the degree required for the 
purpose for which it is to be used ; and 
steel is fortunately of such a nature as 
to admit of being tempered to various 
decrees of hardness. 

Following is a brief description of 
the process of tempering, in which we 
have taken, for purpose of illustration, 
a steel chisel. 

The cutting end of the chisel (that is, 
the part to be tempered) is first heated 
to a red heat in a forge. This end is 
then plunged into cold water, care 
being taken during this operation not 


76 


STANDARD METALS. 


to cool the body of the tool, as its heat 
is needed to afterward produce the 
proper temperature at the end that has 
been cooled. Upon removing- the end 
from the water the heat that is retained 
in the body of the chisel gradually ex¬ 
tends to this end and thereby raises its 
temperature to the degree required for 
the temper. 

As steel changes in temperature its 
color also changes, varying from a 
light straw shade to a deep blue. 
From this fact the workman is en¬ 
abled, by observing the variations in 
color, to determine when the end of the 
tool has reached the temperature neces¬ 
sary to produce the desired temper, 
and as soon as it shows a color indicat¬ 
ing this temperature it is again plunged 
into cold water and allowed to cool. 


STANDARD METALS. 


77 


The darker the color the softer the 
temper obtained. 

To permit the colors to be clearly 
seen the steel is cleaned of oxide after 
the first immersion in the water. 

Steel springs are almost invariably 
tempered by being heated to a red heat 
and then plunged into a bath of oil, 
which gives them a correct and uniform 
temper without unusual care being 
necessary. 


WROUGHT IRON TUBES. 

In the manufacture of wrought iron 
tubes two methods are in common use, 
the smaller sizes being made by what is 
called the “butt weld” process, while 
the method employed in making the 
larger sizes is known as the “lap weld.” 


78 


STANDARD METALS. 


BUTT WELDING. 

For this process the iron is first rolled 
at the rolling - mill to the necessary 
width and thickness for the size of pipe 
required. 

These sheets of iron then go to the 
pipe mill, where they are placed in a 
furnace, and upon reaching a red heat 
are drawn through a bell-shaped die, 
which curls them up until they are 
almost round and the edges are brought 
nearly together. In this form the iron 
is called “skelp.” The skelp is then 
placed in another furnace and upon 
reaching a welding heat is drawn 
through a die, which is belled out on 
one side and through which is a hole 
the size of the outside diameter of the 
pipe. This hole being somewhat smaller 
than the circumference of the skelp, 


STANDARD METALS. 


79 


the edges of the skelp are necessarily 
crowded closely together while being 
drawn through the die, thus forming 
the weld. 

LAP WELDING. 

As the butt weld process does not 
produce a weld of the strength required 
in the larger sizes of pipe, the method 
known as “ lap welding ” has been intro¬ 
duced in the manufacture of such pipe. 

The iron is first prepared at the roll¬ 
ing mill in the same manner as for the 
butt weld process, and is then sent to 
the pipe mill. The next step is “scarf¬ 
ing,” that is, bringing the edges down 
to a knife sharpness. The iron is then 
formed into skelp by being heated in a 
furnace and drawn through a die some¬ 
what similar to the one used in the 

butt weld process, but which, instead 

0 


80 


STANDARD METALS. 


of bringing- the edges nearly together, 
as is done in that method, causes one 
to lap over the other. 

The reader will understand, from the 
description of welding given elsewhere 
in this book, that in order to produce 
a substantial weld the two pieces of 
metal to be joined must be brought 
solidly together under a welding heat 
and pressure. To produce this pressure 
in making lap weld pipe it is necessary 
that there be a resistance on the inside 
of the pipe to the pressure applied on 
the outside, and this resistance is ob¬ 
tained in the following manner: At 
one end of the furnace is a pair of rolls 
grooved to correspond with the outside 
diameter of the pipe to be made, and in 
the center of this groove is placed a 
ball of the same size as the inside 


STANDARD METALS. 


81 


diameter of the pipe. The ball is fas¬ 
tened to the end of a bar somewhat 
smaller and longer than the pipe, and 
this bar is firmly supported at the oppo¬ 
site end so that the ball will be held up 
to its position in the groove of the rolls. 

After the iron has been formed into 
skelp it is placed in another furnace, 
and upon reaching a welding heat, a 
workman at the end of the furnace 
opposite the rolls, by means of a long 
rod, then forces the hot skelp between 
the rolls, by which it is carried over the 
ball and on to the rod supporting the 
ball, the rolls producing the pressure 
on the outside of the skelp, while the 
ball supports the weld on the inside. 
The result is that the lap is forced 
solidly together, and there being in this 
case very much more surface to weld 


82 


STANDARD METALS. 


than is obtained in the butt weld proc¬ 
ess, a weld is produced that has the 
strength required in the larger sizes of 
pipe. 


MOLDING. 

There is probably no branch of me¬ 
chanics that covers so wide and inter¬ 
esting a field as molding. It doubtless 
originated in the manufacture of brick, 
and its fundamental principle lies in 
the process of forming something by 
means of a mold or pattern. 

Bricks were originally formed into a 
square by hand, with the possible aid 
of a straight stick to make the shape 
true. But later the inventor devised a 
box, or mold, the size and shape of the 
brick desired, and by filling it with clay 


STANDARD METALS. 


83 


and turning - it out he quickly produced 
a uniform brick. 

Out of this simple beginning has 
grown an enormous variety of indus¬ 
tries, taking on many forms and com¬ 
plications and producing an endless 
variety of goods. 

The production of terra cotta is but 
one step in advance of brick making, as 
this article is simply an ornamental 
brick. 

The next step brings us to plaster of 
Paris ornaments used in house decora¬ 
tion, the production of which is . very 
similar to that of terra cotta. This 
form of molding has been applied to 
the copying of works of art, wherein 
considerable mechanical skill is re¬ 
quired. Following this we find the 
manufacture of glass in molds, which is 


84 


STANDARD METALS. 


a .step higher in art and skill. To pro¬ 
duce such articles as plates or tumblers 
the melted glass is pressed between 
molds, which gives it the desired shape. 
In the production of bottles the glass is 
first blown to a bulb form, after which 
it is put into a mold and blown until it 
takes the shape of the mold. 

Next comes the molding of soft met¬ 
als, such as zinc, lead, tin, and britannia, 
in metal molds. 

This brings us to an art of still 
greater importance, and one that has 
perhaps done more for mankind than 
all others, namely, that of type-making, 
which is nothing more nor less than a 
development of the original crude proc¬ 
ess of molding. Even printing itself, 
in all its numerous and far-reaching 
modifications, is but an evolution of the 


STANDARD METALS. 


85 


same idea, the paper being- the sub¬ 
stance that receives the impress made 
by the type. 

Coinag-e is also the outgrowth of 
molding, the stamping of a coin differ¬ 
ing from molding only in that both 
sides of the metal are treated by the 
one process at one time. 

With this glance at the far-reaching 
development of the original idea, we 
come to the consideration of mold¬ 
ing as the term is usually applied, 
which covers a line of manufacturing 
so extensive and varied that it is im¬ 
possible to here give more than the 
merest outline of its principles. 

This branch of molding consists of 
the duplication of articles from wooden 
or metal patterns, in sand or loam (in¬ 
stead of in molds made of wood or 


86 STANDARD METALS. 

metal, as in the case of the articles 
previously mentioned), using boxes or 
flasks made in two parts, which are 
guided together by pins. This con¬ 
struction of flasks is necessary, for two 
reasons: First, where the pattern is 
round or oval, or of a shape that can not 
be drawn from the sand unless the 
mold separates at the largest point of 
the pattern, it thus leaves half of its 
impression in each part of the flask. 
Second, the upper part of the flask 
allows the metal to have a pressure, 
or head, which is required in order 
to produce castings free from air¬ 
holes. 

To provide against air-holes it is also 
necessary that the quality of the sand 
should be taken into consideration. 
The hotter the metal is when melted, 


STANDARD METALS. 


87 


the more gas and vapor it will produce 
in the mold, and as the sand must be more 
or less damp in order to mold, it also 
contains substances which will produce 
gases when metals of a high tempera¬ 
ture come in contact with them. There¬ 
fore, the hotter the metal is, the coarser 
should be the sand, in order that the 
gases and vapors may pass through it; 
as otherwise the metal would be dis¬ 
turbed and air-holes would be caused. 
Sand is therefore always selected of a 
quality to correspond with the nature 
of the required casting. 

ALUMINUM. 

QUALITIES. 

In color this metal much resembles 
silver, although instead of being a dead 
white it has a delicate purple tint. 


> < 



88 


STANDARD METALS. 


It melts at a temperature of 1157 de¬ 
grees Fahrenheit. 

It does not volatilize at any temper¬ 
ature ordinarily produced by combustion 
of carbon, even though the temperature 
be kept up for hours. It does, however, 
oxidize. 

It is very ductile and can be rolled 
into sheets .0005 of an inch in thickness, 
or even thinner. It is also beaten into 
sheets in exactly the same manner that 
gold-leaf is hammered. 

Impurities found in manufactured alu¬ 
minum are put there by the manufac¬ 
turers in order to obtain hardness, 
rigidity, and strength. The principal 
alloys used for this purpose are nickel, 
copper, and zinc. 

Aluminum is susceptible of a high 
degree of finish, by polishing or bur- 


STANDARD METALS. 


89 


nishing. It becomes hard by working - , 
or when being spun into shape, drawn 
into wire, or stamped out. It is ren¬ 
dered soft again by annealing, and if re¬ 
quired to be soft for a final operation, it 
must be annealed before being subjected 
to this work. 

By forging and cold-rolling it is given 
rigidity and temper. 

It is the lightest of commercial met¬ 
als, a given bulk of iron being 3 times 
as heavy as a corresponding bulk of alu¬ 
minum ; silver, 4 times as heavy; lead, 
4.8 times; gold, 7.7 times, and platinum 
8.6 times. 


WHERE FOUND. 

Aluminum is found as a coarse white 
sand or gravel, called “corundum.” 

As all clays contain this metal, in 


90 


STANDARD METALS. 


greater or less proportions, it may be 
said that it is found more or less in all 
sections of this country where clay ex¬ 
ists. The principal source of supply, 
for this country, however, is in Georgia. 

HOW PRODUCED. 

Corundum is first reduced by a soda 
process. The ore is then calcined, when 
it resembles flour in fineness and is of a 
gray-white color. 

The metal aluminum as manufactured 
to-day on a commercial basis is made 
entirely by the electrolitic process, this 
having supplanted the sodium process, 
which was discontinued upon the intro¬ 
duction of the methods now employed 
in its production. 

The cost of this metal has been enor¬ 
mously cheapened by the modern proc- 


STANDARD METALS. 


91 


esses employed in its production, its 
price being now about one-half of what 
it was a few years ago. 

USES. 

Aluminum is most extensively used 
in making cast steel, the manufacturers 
of this article using at least two-thirds 
of the whole aluminum output. 

Aluminum is largely employed for 
decorative purposes; also in the stamp¬ 
ing of book-covers, where it takes the 
place of gold-leaf. 

It can be drawn into tubes or wire, 
and is spun or stamped into different 
shapes. It is also cast, drop forged, and, 
in fact, is used in nearly every way that 
steel and copper are employed. 

From the fact that it burns with a 
very brilliant light, it is used in flash- 


92 


STANDARD METALS. 


light photography and in the making of 
fire-works. 

Engravers use this metal for plates, 
domestic utensils are made of it, and 
it is employed extensively in the arts 
and sciences, as neither moist air nor 
sulphur vapor affects it, and it is nearly 
permanent in lustre. 
























